Arc head operating mechanism for searchlights



Sept. 20, 1938. w. H, JACOB! El AL ARC HEAD OPERATING MECHANISM FORSEARCHLIGHTS Filed June 19, 1937 v 3 Sheets-Sheet l .0 A l 9 4 g a Z 5 nr z 55 w 4 0 /I|,\\ m 8 9 f 3 4 ll l l l l IHHI I I l l wH M M FH AUL lI ||||l| 1 1 4 Q m z a m a 7 6 u M 0 & L 2 Z INVENTORS A M70007 flfacob/anofrwne /9.' 7052.-

WITNESSES:

I A TOR Sept. 20, 1938. w. H. JACOB] El AL 7 2,130,846

ARC HEAD OPERATING MECHANISM FOR SEARCHLIGHTS Filed June 19, 1937 3Sheets-Sheet 2 fig: 2.

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WITNESSES; INVEETORZ C Mfl/am/lf 0:0 fi anafru/heiyofif' ATTOR Y w. H.JACOB! El AL 2,130,846

ARC HEAD OPERATING MECHANISM FOR SEARCHLIGHTS Filed June 19, 19:57 3Sheds-Sheet 3 a I a INVENTORS M///0m bf Jacob/ anof/v/nev? Yasf 6/" I'lI, ATTORN Sept. 20, 1938.

WITNESSES:

Patented Sept. 20, 1938 PATENT OFFICE ARC HEAD OPERATING MECHANISM FORSEARCHLIGHTS William H. Jacobi, Wilkinsburg,

A. Yost, Lakewood, Ohio,

Pa., and Irvine assignors to Westinghouse Electric 8; ManufacturingCompany, East Pittsburgh, Pa., a corporation of Pennsylvania ApplicationJune 19, 1937, Serial No. 149,157

11 Claims.

Our invention relates, generally, to are searchlights and, moreparticularly, to a mechanism for manipulating the electrodes andelectrode holders, or are head mechanisms as they are sometimes called,of an arc searchlight.

In the operation of arc searchlights, it is common practice to provide amechanism for controlling the electrodes and to support this mechanismon the outside of the Searchlight drum, usually on the underside of thedrum. Where auxiliary manual adjusting means are provided, it is veryinconvenient to mount said manual means at a point where they arereadily accessible to the operator and still may manipulate the controlmechanism within the drum. Furthermore, such manual controls are usuallyso mounted as to move about a horizontal axis each time the drum ismoved about its horizontal axis. An object of our invention is toprovide a mechanism which shall function to automatically maintain oneelectrode of an arc searchlight in a predetermined position and tomanipulate the other electrode to strike the arc and to thereaftermaintain the other electrode in a predetermined relation witi respect tothe one electrode.

Another object of the invention is to provide a mechanism which shalloperate to automatically feed the electrodes of an arc searchlight to anarc and which functions in response to manual control to change theposition of either of the electrodes.

A further object of our invention is to provide an electrode positioningcontrol for an are searchlight which shall be responsive to bothautomatic and manual operation.

Another object of our invention is to provide a manual control for anelectrode of an are searchlight which shall be manipulated by a controlmember which extends from the Searchlight trunnion and which issubstantially concentric with the axis about which the searchlightrotates in the trunnion.

A further object of the invention is to provide an automatic and amanual control for the electrodes of an arc Searchlight, the automaticcontrol mechanism being housed in the trunnion head plate of thesearchlight drum and rotatable with the drum on its trunnion pivot andthe manual controls being concentric of and extending through thetrunnion pivot.

Another object of the invention is to provide manual control andadjusting mechanisms for the electrodes of an arc searchlight, thecontrols and adjusting mechanisms being concentric with the trunnionbearing and being nested so that some of the controls extend throughother of the controls.

These and other objects and advantages of the invention will be apparentfrom the following description with reference to the accompanyingdrawings, in which:

Figure 1 is a diagrammatic representation of a system for automaticallyand manually control ling the electrodes of an arc searchlight inaccordance with our invention;

Fig. 2 is an elevation view partly in section showing the manner inwhich the automatic control is housed within the trunnion head plate andhow the manual controls extend through the trunnion head, and

Fig. 3 is a plan view of a portion of a searchlight with some or theparts cut away to show the relations of the trunnion head, trunnion headplate and control means for the electrodes.

In practicing our invention, we provide a means for controlling theposition of the negative electrode by the differential motion between aconstant speed motor which regularly feeds the positive electrode and avariable speed motor whose speed may be governed by the arc current orvoltage. The method of controlling this motor speed is not an essentialpart of this invention and is not discussed in detail here. Such asystem as that disclosed in the copending application 'of Oren G.Rutemiller, Serial No. 732,685, filed June 27, 1934, might be used forthis purpose. The regular feed of the positive electrode may beaccomplished by a system which may be the same as that of the copendingapplication of W. R. Farley et a1. Serial No. 149,164, filed June 19,1937, and may comprise a continuously driven constant speed motordriving a mechanism which rotates the positive electrode and which ismade to drive the positive electrode forward by an electromagneticdevice which is intermittently actuated for predetermined adjustableintervals.

The drive from the constant speed motor to the positive electrode passesthrough a difierential gearing arrangement which may be actuatedmanually to adjust the positive carbon. There is a similar diiferentialgearing arrangement in the negative electrode drive with manual meansfor varying the position of the negative electrode.

A manually operated adjusting means is provided for moving the arc headas a unit along the axis of the positive electrode so as to properlyposition the arc with respect to the reflector.

A manually operated adjustment is provided for varying the intervals ofenergization of the electromagnetic positive means. I

These differential drives are" compactly arranged and housed within thetrunnion head plate which extends from the searchlight drum into thetrunnion head. The electrical circuit controller for the electromagneticactuating device for the positive electrode is also housed in thetrunnion head plate and is driven by the constantly rotating motor.

The manual controls for these adjusting devices extend through thetrunnion bearing and are all coaxial therewith. An operating handle isattached to each of the controls and the controls are nested andtelescoped so as to make a very compact concentric arrangement whoseaxis will not shift when the searchlight drum is rotated about its horizntal trunnion axis.

Referring to Fig. 1, the mechanism 4 shown enclosed in the broken lineis the control mechanism for the electrodes of the searchlight and isvery similar to that shown in the French patent to Breguet, No. 697,990.This mechanism comprises a motor 5 which drives an actuating mechanism 6for the positive electrode 55 through a mechanical linkage whichincludes worm gear I, worm wheel 8, gears 3 and ill, a differential geararrangement H, gears l2, l3, I4 and I5, 2. linkage including universaljoint l6, shaft 12 and universal joint i1 and worm gear l8.

Motor 5 also drives a gear I9 which is a part of a differential geararrangement 26 and which cooperates with gear 2 I, which is driven bymotor 22 to control the movement of floating differential gears 23 and24. The differential in the movement electrode actuating between gearsl9 and 2| is transmitted by gears 23 and 24 to shaft 25, which drivesthe feed mechanism 26 for the negative electrode 54 through a mechanicallinkage which includes gears 21 and 28, differential gear arrangement28, gears 36, 3|, 32 and 33 and a linkage which includes universal joint34, shaft H and universal joint 35.

Motor 5 is continuously driven at a constant speed and motor 22 iscontinuously driven at a speed which may vary with the potential betweenthe positive and negative electrodes or the current flowing in thepositive and negative electrodes. The operation of such a system isfully explained in the copending application of Oren G. Rutemiller,hereinbefore referred to.

A manual control is provided to supplement the motor driven control ofeach of the electrodes. For the negative electrode this controlcomprises a handwheel- 36 which actuates a hollow shaft 31 to turn gear36, which, in turn, causes the rotation of gear 36 of the difierentialgearing arrangement 28 through gears 40, 4|, 42, 43 and 44. It will bereadily seen that rotation of handwheel 36 will cause movement of thenegative electrode in an advancing or retracting direction, dependingupon the direction in which handwheel 36 is turned. Similarly, handwheel45 controls the movement of the positive electrode through shaft 46,gears 41, 48, 43, 50, 5|, 52 and 53.

The positive and negative electrodes 55 and 54 are mounted upon amovable arc head mechanism, or electrode support, 56 which may be movedto change the position of the are by the rotation of gear 51, whichcauses screw threads 58 to move arc head mechanism 56. Gear 51 isactuated by handwheel 53 through a linkage which includes control shaft66, universal joint 6|, shaft '62, universal joint 63 and gear 64.

The operating mechanism for the positive electrode may be the same asthat disclosed in the hereinbefore referred to application of Farley etal. and may include en electromagnetic device 65 which intermittentlycauses advancing of the electrode 55 under control of a circuit which isgoverned by the contacting device 66. The exact circuits for thiscontrol are not shown or described, since they are fully set forth inthe above mentioned application. Variation of the periods of actuationof magnet 65 is secured by movement of contact device '61 laterallyalong the surface of rotating contactor 66 by means of operating handle68 which is connected by shaft 69 to the contact device 61. The contactdrum 66 is continuously rotated at a constant speed by motor 5 throughgear elements I and III.

Referring to Fig. 2, there is shown the mechanism 4 supported on theshaft 13 which, in turn, is secured to plate member 14. Plate member 14is secured to the drum 15 of the searchlight in the inside of the drumto cover the opening 16 in the side of the drum and has the operatingshafts for the positive and negative electrodes and the are headadjusting mechanism extending through it. On the outside of the drum 15there is secured a trunnion head plate in the form of a housing 11. Thishousing ll forms a closure for the opening 16 in the drum l5 and forms areceptacle into which the operating mechanism 4 extends. Trunnion head18 is supported on trunnion l9 and carries bearing members 86 whichprovide a support for rotation of the drum about a horizontal axis. Thedrum is supported for rotation on these hearings by extension 8i onhousing 'Il which cooperates with bearings 86. The operating shafts 60,46, 31 and 69 are concentric and extend through the bearing to theoutside of the trunnion coaxial with the bearing, so that they may beconvenient to an operator standing beside the trunnion.

Referring to Fig. 3, there is shown a plan view of part of a searchlightwith some of the parts in section and others broken away to show therelative positions of the parts hereinbefore described. The plate 14 maybe removed from the drum 15 by removing screw bolts 82 and 83 and thewhole operating mechanism may be removed as a unit with the plate 14 bydisconnecting shafts Ii, 62 and I2 and removing operating handles 53,45, 36 and 68. This arrangement facilitates inspection, maintenance andrepair of the operating mechanism 4. The mechanism 4 is protected fromheat radiation from the are by a plate 84 which is supported on andspaced from the plate 14 between the arc and plate 14. The mechanism isoiled without removing it from the casing through convenient oilingtubes 85 and 85.

It will be seen that we have provided a compact arrangement of theoperating elements for the electrodes and the arc head of an aresearchlight, have provided a housing for these operating elements whichalso serves as the support for the rotation of the drum around ahorizontal axis and have made this mechanism readily removable as a unitfrom this housing and have provided auxiliary control elements readilyaccessible from the outside of the drum and positioned along thehorizontal axis.

In compliance with the requirements of the patent statutes, we haveshown and described herein a preferred embodiment of our invention. Itis understood, however, that the invention is not limited to the preciseconstruction shown and described. It is capable of modification by oneskilled in the art, the embodiments herein shown being merelyillustrative of the principles of our invention.

We claim as our invention:

1. In an arc searchlight, a trunnion, a trunnion head compartment on thedrum of said searchlight, an end compartment on said trunnion. meansmounting said trunnion head compartment-for rotation about a horizontalaxis in said end compartment and control means for the electrodes ofsaid searchlight mounted in said trunnion head compartment.

2. In an arc searchlight, a trunnion, an end compartment on saidtrunnion, a trunnion head compartment on the drum of the searchlight,

means for mounting said trunnion head compartment for rotation about ahorizontal axis in said end compartment, manual control means for theelectrodes of said searchlight mounted in said trunnion headcompartment, and operating means for said control means extending fromsaid end compartment.

3. In an arc searchlight, a control mechanism for the electrodes of thesearchlight, a trunnion having an end compartment, a searchlight drumhaving an opening in one side thereof, a plate removably mounted on theinside of said drum in a position to cover said opening, a headcompartment mounted on the outside of the drum in a position to coversaid opening and to form an outwardly extending compartment on saiddrum, means for mounting said head compartment in said trunnion endcompartment to provide a horizontal axis around which the drum mayrotate, and means for mounting said electrode control mechanism uponsaid plate within said head compartment so that said control mechanismmay be removed with said plate.

4. In an arc searchlight, an electrode support, an operating mechanismfor the electrodes mounted upon the electrode support a controlmechanism for said operating mechanism, a trunnion having an endcompartment, a searchlight drum having an opening in one side thereof, aplate removably mounted on the inside of said drum in a position tocover said opening, a head compartment on the outside of said drum in aposition to cover said opening and to form an outwardly extendingcompartment on said drum, means for mounting said head compartment insaid trunnion end compartment to provide a horizontal axis around whichthe drum may rotate, means for mounting said electrode control mechanismupon said plate within said head compartment so that said controlmechanism may be removed with said plate, and control means extendingthrough said plate from said control mechanism to said operatingmechanism.

5. In an arc searchlight, electrode actuating means, a mechanism forcontrolling the actuation of the electrodes of the searchlight, saidmechanism comprising two motors, means including differential geararrangements for connecting each of said motors to separate ones of saidelectrode actuating means, manually controlled means acting upon each ofsaid difierential gear arrangements for varying the actuation of saidelectrodes, a trunnion, a housing on the searchlight drum having meansfor mounting the drum on said trunnion for rotation about a horizontalaxis, said controlling mechanism being contained within said housing andactuating means for said manually controlled means extending throughsaid drum mounting means coaxial with said horizontal axis.

6. In an arc searchlight, electrode actuating means, a mechanism forcontrolling the actuation of the electrodes of the searchlight, saidmechanism comprising two motors, means including difierential geararrangements for connecting each of said motors to separate ones of saidelectrode actuating means, manually controlled means acting upon each ofsaid difierential gear arrangements for varying the actuation of saidelectrodes, a trunnion, a housing on the searchlight drum having meansfor mounting the drum on said trunnion for rotation about a horizontalaxis, said controlling mechanism being contained within said housing andactuating means for said manually controlled means extending throughsaid drum mounting means coaxial with said horizontal axis, an arc headsupporting said electrodes and their respective actuating means and amanually controlled means for changing the position of said are head,said last named manually controlled means including an actuating meansgrouped with, and concentric of, said actuating means for said firstmanually controlled means.

7. In an arc searchlight, electrode actuating means, a mechanism forcontrolling the actuation of the electrodes of the searchlight, saidmechanism comprising two motors, means including differential geararrangements for connecting each of said motors to separate ones of saidelectrode actuating means, manually controlled means acting upon each ofsaid difierential gear arrangements for varying the actuation of saidelectrodes, a trunnion, a housing on the searchlight drum having meansfor mounting the drum on said trunnion for rotation about a horizontalaxis, said controlling mechanism being contained within said housing andactuating means for said manually controlled means extending throughsaid drum mounting means coaxial with said horizontal axis, saidmechanism for controlling the actuation of one of said electrodesincluding an electromagnet, an adjustable interrupter for saidelectromagnet driven by one of said motors and mounted in said housingand manual adjusting means for said interrupter including an actuatingmeans grouped with, and concentric of, said actuating means for saidfirst manually controlled means.

8. In an arc searchlight, electrode actuating means, a mechanism forcontrolling the actuation of the electrodes of the searchlight, saidmechanism comprising two motors, means including difierential geararrangements for connecting each of said motors to separate ones of saidelectrode actuating means, manually controlled means acting upon each ofsaid difierential gear arrangements for varying the actuation of saidelectrodes, a trunnion, a housing on the searchlight drum havingmeansfor mounting the drum on said trunnion for rotation about ahorizontal axis, said controlling mechanism being contained within saidhousing and actuating means for said manually controlled means extendingthrough said drum mounting means coaxial with said horizontal axis, saidmechanism for controlling the actuation of one of said electrodesincluding an electromagnet, an adjustable interrupter for saidelectromagnet driven by one of said motors and mounted in said housingand manual adjusting means for said interrupter including an actuatingmeans grouped with, and concentric of, said actuating means for saidfirst manually controlled means, the drum side of said housingcomprising a removable cover plate and means for mounting said mechanismon said cover plate.

9. In an arc searchlighthaving a Searchlight drum, an arc head uponwhich the arcing electrodes are supported in the drum and means forproducing a beam, in combination, means for mounting the Searchlightdrum on an axis which is substantially normal to the normal direction ofthe beam projected by the Searchlight, and means for manually adjustingthe position of the arc head as a unit including a control memberextending to the outside of the drum along said axis.

10. In an arc Searchlight having a Searchlight drum, an actuatingmechanism for each 01' its electrodes in the drum and means forproducing a beam, in combination, means for mounting the Searchlightdrum on an axis which is substantially normal to the normal direction ofbeam projected by the searchlight, and means for manually controllingthe electrode actuating mechanisms comprising a linkage connected toeach of the actuating mechanisms and extending to the outside of thedrum along said axis.

11. In an arc Searchlight having a Searchlight drum, means for producinga beam, an actuating mechanism for each of its electrodes in the drumand a, mechanism for adjusting the position of the arc head as a unit inthe drum, in combination, means for mounting the searchlight drum on anaxis which is substantially normal to the normal direction of the beamprojected by the Searchlight, and means for manually controlling theelectrode actuating mechanisms and the arc head adjusting mechanismcomprising a linkage connected to each of the mechanisms and extendingto the outside of the drum parallel with said axis.

WILLIAM H. JACOBI. IRVINE A. YOST.

